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<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <script>
      const arr = [1, 2, 3, 4]

      //filter 筛选数组
      //选出数组中的偶数
      //选出数组中的奇数
      //选出大于2的项

      //   const newArr = arr.filter(function (item, index, array) {
      //     return item > 2
      //   })

      //   const newArr = arr.filter((item) => item > 2)

      // const newArr = arr.filter(function (item, index, array) {
      //   return item > 2
      // })

      const newArr = arr.filter((item) => {
        item = item + 1
      })

      console.log(newArr) //[1,2,3,4] //[]
    </script>
  </body>
</html>
